|  | // Copyright 2013 The Chromium Authors. All rights reserved. | 
|  | // Use of this source code is governed by a BSD-style license that can be | 
|  | // found in the LICENSE file. | 
|  |  | 
|  | #ifndef BASE_POWER_MONITOR_POWER_OBSERVER_H_ | 
|  | #define BASE_POWER_MONITOR_POWER_OBSERVER_H_ | 
|  |  | 
|  | #include "base/base_export.h" | 
|  | #include "base/compiler_specific.h" | 
|  |  | 
|  | namespace base { | 
|  |  | 
|  | class BASE_EXPORT PowerObserver { | 
|  | public: | 
|  | // Notification of a change in power status of the computer, such | 
|  | // as from switching between battery and A/C power. | 
|  | virtual void OnPowerStateChange(bool on_battery_power) {}; | 
|  |  | 
|  | // Notification that the system is suspending. | 
|  | virtual void OnSuspend() {} | 
|  |  | 
|  | // Notification that the system is resuming. | 
|  | virtual void OnResume() {} | 
|  |  | 
|  | protected: | 
|  | virtual ~PowerObserver() = default; | 
|  | }; | 
|  |  | 
|  | }  // namespace base | 
|  |  | 
|  | #endif  // BASE_POWER_MONITOR_POWER_OBSERVER_H_ |